A building with 100 sqm roof area is connected to a 72 cum rainwater collection tank. If the rainfall is 60 mm per hour and the loss during water storage is 20%, then the time taken to fill the tank completely is_______ hours.

• A. 20.0 to 15.0
• B. 25.0 to 15.0
• C. 15.0 to 15.0
• D. 24.0 to 15.0